textarea {  
    display: inline-block;
    height: 200px;  
    font-size: 16px;  
}  
  
.line-numbers {  
    vertical-align: top;
    border-right: 1px solid #ccc; 
    padding-right: 10px;  
    color: #999;  
    display: inline-block;
    user-select: none; /* Prevent text selection in line numbers */  
    pointer-events: none; /* Prevent interactions (clicks, etc.) in line numbers */  
}  
  
.line-number {  
    counter-increment: line;  
    content: counter(line);  
    display: block;  
    line-height: 1.5; /* Match the line height of the textarea */  
    margin-top: -1px; /* Compensate for the border-bottom of the previous line number */  
}  